Mechanism of resistance degradation of lead magnesium Niobate-based ferroelectrics induced by hydrogen reduction during electroplating

Abstract

Resistive leakage of lead magnesium niobate (PMN) based relaxor ferroelectrics after nickel electroplating was investigated through X-ray photoelectronic spectroscopy (XPS) analysis and annealing experiments in oxygen and argon. It was found that the resistivity of the ceramics declined nonlinearly with the electroplating time. XPS analysis suggested that the reduction of Nb⁵⁺ to Nb⁴⁺ by hydrogen during electroplating played an important role in the degradation. It was also noted that the degraded specimen can recover its properties completely after oxygen annealing at 600°C for 1 hour through the oxidation of Nb⁴⁺ to Nb⁵⁺. In contrast, almost no oxidization of Nb⁴⁺ and improvement of the degradation were observed for the degraded specimen after argon annealing. Therefore, it was concluded that the resistance degradation of the PMN-based relaxor ferroelectrics during electroplating must be ascribed to the oxygen loss and the reduction of Nb⁵⁺ to Nb⁴⁺.